Interactivity with projected content including gestures and/or virtual touch is evolutionary and may be accomplished in many ways including but not limited to Retroreflection and various depth sensing techniques (viz., Triangulation, Structured Light, Time of Flight (TOF), etc.). Spatially resolving the intruding object such as a finger, hand, stylus, and so on, yields information that can be packetized and passed on to the host OS as a touch or mouse event for example. Unlike a physical touchscreen, projected content poses a unique dilemma. Interacting with projected content by hovering in the projection cone or projection field of view (FOV) would cause image occlusion to the user or viewer because of the intruding object being between the projector and projection surface. This would give rise to shadows that might be undesirable in certain use cases. Further, the physical environment might also be non-conducive to such interaction.
For example, the projector may be an ultra-short throw one where the projected image is on a surface that is not easily accessible to the user or, even if accessible, the shadows created cover large sections of the projected content. If the projector were ceiling mounted, large portions of the projection cone or FOV might be entirely inaccessible and, even if accessible, might only be accessible when the user is very close to the projection screen. In the case of an automotive head up display (HUD), the projection cone or FOV might be entirely inaccessible, or the placement might be non-ergonomic for interactivity or lead to safety concerns. In the case of eyewear such as augmented or virtual reality eyewear, the region between the projector and image surface might be inaccessible or, if accessible, would cause occlusion or eclipsing most of the projected content. In a standard scenario with a projector set on a table, the use case might deem the projection cone or FOV cumbersome to interact with or altogether inaccessible.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.